Question

Which table shows a proportional relationship between x and y?

A.
x y
2 9
4 18
6 27
8 36
10 45
B.
x y
2 2
4 8
6 18
8 32
10 50
C.
x y
1 4
2 7
3 10
4 13
5 16
D.
x y
1 5
2 6
3 7
4 8
5 9

Answer 1

A. Because y/x = 9/2 = 18/4 = 27/6 = 36/8 = 45/10 = 4.5, so y = 4.5x for every pair (a constant ratio), which is a proportional relationship.